const STORAGE_KEY='mall';
export default{
    setItem(key,value,module_name){
        if(module_name){
            let val=this.getItem(module_name)
            val[key]=value
            this.setItem(module_name,val)
        }else{
            let val=this.getStorage()
            val[key]=value
            window.sessionStorage.setItem(STORAGE_KEY,JSON.stringify(val))  
        }
    },
    //获取模块下面的属性user下面的userName
    getItem(key,module_name){
        if(module_name){
            let val=this.getItem(module_name)
            if(val) return val[key]
        }
        return this.getStorage()[key]
    },
    getStorage(){
        JSON.parse(window.sessionStorage.getItem(STORAGE_KEY) ||'{}')
    },
    clear(key,module_name){
        let val=this.getStorage()
        if(module_name){
            if(!val[module_name]) return
            delete val[module_name][key]
        }else{
            delete val[key]
        }
        this.setItem(STORAGE_KEY,val)
    }
}